VE LOCIT Y 



OF STREAM 



OF CRESTS RELATIVE 

 TO MEDIUM 



OF WAVE ENERGY 



RELATIVE TO MEDIUM 



OF WAVE ENERGY 4 



RELATIVE TO OBSTACLE U~c 



(a) Pattern of waves generated. 



C-U 



0.9 



(b) Graph which plots against X/h, for stationary waves of length X on a stream of depth h, 

 with one-seventh power distribution of velocity and mean speed V,„, the ratio to V m of the 

 wave velocity c which waves of that length would have on still water. 



Figure 2. Two-dimensional wave making. 



8. Three-dimensional wave pattern due to an obstacle 



I will now discuss briefly the three-dimensional pattern of stationary waves due 

 to an obstacle at a point in a running stream (Fig. 3). Oblique waves are then present, 

 and for them to be stationary those of velocity c must set themselves at an angle 



21 



